The 13-year-old conservationist returned to The Tonight Show Thursday after making his debut on the show in February. His first visit reached 54 million people on Facebook—an impressive number for any star, let alone one one who's fairly new to the international spotlight. "It was such an honor to be on the show," Robert told Jimmy. "One of the friends who was traveling with us at the time kept going, 'Look! It's up to 10 million! Look! It's at 20 million!' It was an incredible experience for me, so thank you so much for having me back. We have so much fun."

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After Robert's first appearance, Jimmy said, "A lot of the viewers said you look like your dad. You're a spitting image. He'd be so proud." Jimmy then showed side-by-side photos of Robert and his father, the late Steve Irwin, at age 13. "It's a bit wild. When my mom first showed this to me, I thought it was me," the teen admitted. "I can't tell them apart. I said, 'It's me. What's the big deal?' Until you look at dad's shirt, you don't even realize that it's two different people."

Moments later, Robert introduced Jimmy to Jane, a dictator scorpion. "You're welcome to come close," he said, but the host scooted away from his desk. "She's actually quite friendly."

"Isn't she just magnificent?" Robert said as the nocturnal scorpion crawled over his hands. "The bigger the pinchers, the less venomous they are. But if they have smaller pinchers, that means they pack a lot of venom." While Jimmy appreciated the info, he said, "That thing frightens me."

Robert then introduced him to two baby black bears—one of which bit Jimmy's hand. "I think she's just chewing on your thumbs a little bit," Robert said, noting that they're "hyperactive" little animals. "These ones are only a couple months old. They will get larger than this, though."

Eventually, Robert said, the bears will weigh about 300 lbs. each. At one point, Jimmy nearly kissed one of the cubs. "That was the closest I ever came to a bear," he said. "This is so cool."

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Robert then brought out two legless lizards. "They're not snakes," he told Jimmy. "He actually has ears; snakes don't have ears. That's one of the biggest reasons you can tell the difference." The legless lizards didn't stay out long, as Jimmy thought they were the "creepiest things" ever.

Jimmy met a binturong next. "Come on your hands and knees, and just let him smell your head," Robert told him. "This one is from Southeast Asia, and they love those rainforest areas."

"My favorite thing about them is that they smell like popcorn," Robert added. "It's amazing!"

The Roots helped Robert show off a green aracari. "They live in South America. They're one of the smallest species of toucan. They're very inquisitive. They're amazing at picking fruit from trees," he said, using Captain Kirk Douglas to demonstrate. Robert promised "one more surprise," so he asked Fallon to join him across the studio among the audience. "Here's a little bit of food. If you want to put out your hand, Beatrice is going to fly to you—here she comes!"